Lookalikes: The variability of the species of Aspicilia in both thallus morphology & chmistry makes this an especially difficult group to identify As the taxonomy has never been adequately worked out for North American species, distribution maps are either not presented here or should be regarded as tentative. The pale exciple, large spores, & beaded paraphyses distinguish Aspicilia from other genera with immersed, disk-like apothecia, such as Bellemeria, lecidea, Amygdalaria, & Acarosporta. (see also notes on Lecanora oreinoides under Buelia spuria). Hymenelia & Ionaspis are closely related but generally have smaller spores, paler apothecia (with different pigments if black), & lack lichen substances in the thallus.